Summary
Rothmund-Thomson syndrome (RTS) is characterized by skin atrophy, skin pigmentations and telangiectasia. It is frequently accompanied by juvenile cataract, postnatal growth retardation, skeletal abnormalities (mainly osteopenia and defects of the radial ray: thumb appendages, hypoplasia or aplasia of the thumbs, or radial aplasia), premature ageing and predisposition to cancer (especially osteosarcoma). Additional findings include saddle nose, abnormal hair growth and hypogonadism. A study of a cohort of 41 patients with RTS revealed that the age at diagnosis ranged from 9 months to 42 years. There were more males than females (28 males, 13 females). The major findings were poikilodermia (100%), radial ray defects (20%), cataract (6%), and gastrointestinal symptoms (17%). Thirteen patients (32%) had an osteosarcoma and one had skin cancer. The gastrointestinal findings were feeding problems in infants (chronic emesis, diarrhea and duodenal stenosis in a single case). The authors recommended a baseline skeletal radiography of the long bones at 5 years of age for all RTS patients, to help subsequent interpretation of clinical suspicion of osteosarcoma. RTS is an autosomal recessively inherited condition caused by mutations in the helicase gene, RECQL4. A malfunction or absence of specific RecQ-family helicases causes several human diseases: Bloom syndrome, Werner syndrome and RTS. These diseases have overlapping clinical features and predisposition to cancer is a common feature of these syndromes. In contrast, RAPADILINO syndrome, which is also caused by mutations in the RECQL4 gene, is not associated with a significant cancer risk. A recent study of an international cohort found that 11 out of 23 patients with RTS had been diagnosed with osteosarcoma. The diagnosis of RTS should be considered in all patients with osteogenic sarcoma, particularly if associated with skin changes. *Author: Orphanet (January 2005)*.
